nettleton



' @uiten tetes` getarnt @frn4 JOHN L.V NETTLETON, 0F NEW HAVEN, CONNECTICUT.

I Batters Pqfte'nt No. 68,453, lated September 8, 186,7.

y -IMIROVED TOOL-i.

V' l'O ALL WHOM IT MAY CONCERN: Be it known that I, JOHN L. NETTLETON, of the citygn'nd county of New Haven, inthe State-of Connecticut,V

have' invented a new and hseful Improvement in AdjustubleDogs for'TurningfLaths,j&cl; and I do-her'eby declare that the following is-a full, clear, andexact description of the construction, character, and'operation 4 of thclsameu, referencek bcipg had to the accompanying drawings,whieh inakolvpartof'this specification, vin

which- Figure 1 is'a perspective view of the .complete dog, showing its several parta-'except the*v insideof Vthe vibrating ratchets and their connections withV the lracks. l i I' Figure 2 .is a section of one of the racks and one of the vibratingiratchets in their proper connection.- My improvement consists in so constructing the dog with two'pnr'allel rack-bars, ou which'theadjustablev part slides, thatI can slide the adjustable pai-tat lonce to the desired position, and's'o that, when desirable, I can attachand detach the idog, while the-article to be turned is in its place in or on the common centres. I make the permanent or stationary part of vthedog ofmalleable cast iron, or any other suitable material, with a. crosshead,ras A, iig. 1,' and two parallel bars, B and C, set at right angles to the cross-head, and on theA` Y outer edges of these bars B-.and C, I make racks with their teeth of the ratchet shape, pointing *toward the crosshead, or so that when engaged with the `teeth of the vibrating ratchet, as shown at a fig. 2, the sliding part D 'cannot recede from' the crosslhead A. These racks may be of the same piece orpart with the bars B and C, or -they may be made of` steel andA attached by means of screws, dove-tailing, or otherwise; `and, should -.the iron `,teeth fail, by wear orbreakage, the vbars maybe faced with steel or otherwise; and, if thought be'st, `t he teeth Y mayv be on the inner edges of the bars B and C. I make the sliding or `adjustable part of malleablecast iron, 0r`any other suitable material, substantially of the shape shown atfD, g. 1, with two mortises, 'as indicated at b and c, fitted to receive land slide upon: the parallel'rack-bars B and C, asshown in fig. 1. In the-two ends of -this adjustable ban D, and `connected with the mortises, I t two vibrating ratchets, as lindicated at a, Eg'. 1, the teeth of which work'in those of the racks on the bars B and C,as shown in ig. 2. I secure l:hese'1ntcl1eter by jointor fnlcrum-pins, as indicated at cl and d, so that they may be readily moved intoiand outof gear with the` i .teeth of' therncli` by swinging on those pins, or a' diagonal slot may be cut (as indicated by dots in iig. 2) to slide onthe lpin, 'or any other convenient means may be used for throwing them into and outof-gear, as found I most convenient. In 4the centre of -the bar D, I cut a V-shnped groove, as shown at g, and, if thoughtbest, also mill out a segment of acircle, ns shown at h hrwhioh serves to hold the articlebeing turned or dressed at right angles to the bar D and cross-hend A, and on the central part of .the bar D have a suitable projecting'arm or bar, asshown. at E, which is to be placed in the 'slot or guide of the revolving head or face plate of the lathe iu the usual way. In the cross-head A, I t aset-screw, asshown at' G, bywhich' vtobind orpivnch the articlebeing turned after thc sliding-bar' D has' been brought up to and secured in its proper position for use.

Having made the several parts, as before described, I place. the dog on the article to be-turned and bring the sliding-barD up to it, (as thcteeth of the ratchet a will lpass freely over the-teeth in" the racks B and C -when moved in that directiom) and forceor allow the teeth of theratchets, as a, to fall into the teeth 'of tho racks, as shown in iig; 2, when the bnr D willbe held frmlyin-its place. -I then tnrn inthe binding-screw G, when the article will be firmly secured in the dog;i and when the projecting arm or rod E andthe centres are in place all maybe revolved together wit-litho face plate of the lathe. To dog or undo'g an article while i'u the 'Y centres, I haveonly to draw back the ratchets, as a, and slip the slide D 'oli' of the bersl'i and C', when all will be'opcn to be put on or taken off, and when` the article is between the bars( B and C the cross-bar D may be slipped on again to close it, as before. i

What I claim as my invention, and desire to -secure by Letters Patent, is t The combinatioxfof thc sliding-bnr D and its movable ratchet-teeth a with v.the parallel rack-bars B and C and cross-bar A, when all the parts are constructed, connected, and littedfor use, substantially as herein described and set forth. I' v JOHN L. NETTLETON.- Witnesses: l

H. E. TALMAGE, R. Frrzunnsnn. 

